Vaccines: Collateral Risks and the Quest for Herd Immunity


It has just over a year since the disease caused by SARS-CoV-2 was declared a global pandemic by the World Health Organisation (WHO). At that time, though there was considerable global panic, many had limited understanding of that declaration. For any disease to be considered a pandemic, three things ought to happen. Initially, there must be evidence that the pathogen of concern is significant infectious. Then, there must proof that it can cause considerable mortality. Finally, that its spread is global or has the potential to be global.  There is no dispute looking back that COVID-19 has satisfied all these and caused even more havoc. As it stands, the scale of job losses, the shrinking of the global as well as national economies, the spate of national and individual indebtedness and the exposure of inadequacies in most health systems are issues that have been brought to the fore and need to be addressed. Rectifying these in a world that may never return to the default will require some tough decisions; all of which are underpinned by the ability to insure humankind against mass outbreaks in the future. 

As at the time the global pandemic was declared, it was clear that the only sure way to end this was through the development of a vaccine. Such was the caution at the time that the world would have been pleased with a single viable vaccine. Today, we have twelve vaccines with Emergency Use Authorisation (EUA) across the world. No mean achievement for science, in that before COVID-19, scientist had never developed a vaccine in less than 7-years. The downside is the concern that the process has been rushed and patient safety  has been sacrificed on the altar of necessity and expediency.  Though global medicine regulators such as the United States Food and Drugs Authority, the European Medicines Agency, the Medicines and Health Products Regulatory Authority, and the WHO have been at pains to explain away these concerns, many are still perturbed. This situation is not helped by the constant quest by some to spread falsehoods and exploit any cautions to fuel their beliefs. Thus, it is not surprising that the latest information regarding a possible link between blood clotting and vaccination has led to an uproar.

With over 400 million people across the globe vaccinated so far, we believe society should be looking at the data on benefits and risks to make an informed decision as to whether or not granting these vaccines EUA was a step in the right direction. Thus far, most of the data available on the impact of vaccines has come from Israel and the United Kingdom. The findings from these countries have been from over 10 million people of varied gender, age, risk profile and occupations. It is important to state that these numbers are larger than any sample for clinical trials of any medicine ever made. According to research published in the New England Journal of Medicine by the Clalit Institute for Research that compared 596,618 people who had been newly vaccinated in Israel and matched them to unvaccinated controls, two doses of the Pfizer mRNA vaccine reduced symptomatic cases by 94%, hospitalisation by 87%, and severe COVID-19 by 92%. These numbers are of significant importance because without hospitalisation and severe illness, the likelihood of mortality is significantly mitigated.

The SIREN (Sarscov2 Immunity & Reinfection Evaluation) by Public Health England (PHE) monitored 40,000 healthcare workers over 12 months to investigate COVID-19 reinfection rates and immune response, found that that healthcare workers were 72% less likely to develop infection (with or without symptoms) after one dose of the vaccine, rising to 86% after the second dose. This was followed by data released by Public Health Scotland (PHS) and PHE from vaccinations in people over the age of 70-years indicating that both the Pfizer and AstraZeneca vaccines were highly effective in reducing COVID-19 infections.  Their data suggested that 4-weeks after the first dose, infection rate drop ranged between 57 and 61% for one dose of Pfizer and between 60 and 73% for the Oxford-AstraZeneca vaccine.

These findings caused countries in the European Union to reverse their earlier objection to the use of the AstraZeneca vaccine in people over the age of 65-years and demand on the pharmaceutical company to step up vaccine supplies to the bloc. With such a copious consumption of humble pie, one would have thought that this will have been the end of the misgivings that had clouded the use of vaccines generally but the AstraZeneca vaccine specifically. However, this has not been the case following the reports of potential blood clots associated with vaccination in Denmark. 

We find these vaccine negativity views concerning, considering that benefit-risk calculations in health are made based on probabilities of adverse events occurring amongst other things. Though not established yet, assuming a causal relationship were to be established linking these blood clots to a specific vaccine, will the incidence be statistically significant to require halting vaccinations whilst this pandemic rages on? With the latest evidence indicating that the vaccine stops asymptomatic transmission and with case numbers rising in Europe, will the potential mortality due to this rare event exceed the deaths that will occur due to infections with this pathogen? With the WHO coming out to say that its expert analysis of the safety does not suggest a causal relationship, is there the likelihood that this vaccine will be withdrawn? If the answers to these questions are “no” should the world have gone into overdrive? We leave the reader to draw a conclusion based on the evidence.

For those who have concerns about the mild to moderate side effects such as pain at the injection site, slightly elevated temperature, feverishness, nausea and vomiting and are concerned about experiencing these again with a second dose; we will want to assure you that uncomfortable as these may be, they were all expected. We say this because these are known side effects of most vaccines in clinical use. More importantly with a high probability that many could have been infected by the SARS-CoV-2 virus without knowing, others in the population could have pre-existing antibodies, resulting in their immune system responding to any vaccine as though it were a new infection. This for us is a positive signal and must not dissuade anyone from going for their second dose. If anything, it should reassure all that the vaccines are working.

If you are in this category, try balancing the side effects you experienced with the risk of contracting COVID-19. Whilst at it, think of the risks to society; the psychological, economic, chronic disease burden and the hangover effects of this pandemic which may be with us for at least another decade. Ask yourself, “Which collateral inconvenience is best for humankind?”. We have our minds made up on what collateral damage we are prepared to live with and that is to get vaccinated even if side effects occur.

Writer: Dr Kwame Sarpong – Pharmacist, CDD fellow – Ghana



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